Move extensions directories to core_extensions

4 files changed, 69 insertions, 0 deletions

diff --git a/lib/arel/algebra/core_extensions/class.rb b/lib/arel/algebra/core_extensions/class.rb
new file mode 100644
index 0000000000..d0894931da
--- /dev/null
+++ b/lib/arel/algebra/core_extensions/class.rb
@@ -0,0 +1,32 @@
+module Arel
+  module ClassExtensions
+    def attributes(*attrs)
+      @attributes = attrs
+      attr_reader(*attrs)
+    end
+
+    def deriving(*methods)
+      methods.each { |m| derive m }
+    end
+
+    def derive(method_name)
+      methods = {
+        :initialize => "
+          def #{method_name}(#{@attributes.join(',')})
+            #{@attributes.collect { |a| "@#{a} = #{a}" }.join("\n")}
+          end
+        ",
+        :== => "
+          def ==(other)
+            #{name} === other &&
+            #{@attributes.collect { |a| "@#{a} == other.#{a}" }.join(" &&\n")}
+          end
+        "
+      }
+      class_eval methods[method_name], __FILE__, __LINE__
+    end
+
+    Class.send(:include, self)
+  end
+end
+
diff --git a/lib/arel/algebra/core_extensions/hash.rb b/lib/arel/algebra/core_extensions/hash.rb
new file mode 100644
index 0000000000..c64225f685
--- /dev/null
+++ b/lib/arel/algebra/core_extensions/hash.rb
@@ -0,0 +1,11 @@
+module Arel
+  module HashExtensions
+    def bind(relation)
+      inject({}) do |bound, (key, value)|
+        bound.merge(key.bind(relation) => value.bind(relation))
+      end
+    end
+
+    Hash.send(:include, self)
+  end
+end
diff --git a/lib/arel/algebra/core_extensions/object.rb b/lib/arel/algebra/core_extensions/object.rb
new file mode 100644
index 0000000000..85a4d951a4
--- /dev/null
+++ b/lib/arel/algebra/core_extensions/object.rb
@@ -0,0 +1,17 @@
+module Arel
+  module ObjectExtensions
+    def bind(relation)
+      Arel::Value.new(self, relation)
+    end
+
+    def find_correlate_in(relation)
+      bind(relation)
+    end
+
+    def let
+      yield(self)
+    end
+
+    Object.send(:include, self)
+  end
+end
diff --git a/lib/arel/algebra/core_extensions/symbol.rb b/lib/arel/algebra/core_extensions/symbol.rb
new file mode 100644
index 0000000000..f575ad533a
--- /dev/null
+++ b/lib/arel/algebra/core_extensions/symbol.rb
@@ -0,0 +1,9 @@
+module Arel
+  module SymbolExtensions
+    def to_attribute(relation)
+      Arel::Attribute.new(relation, self)
+    end
+
+    Symbol.send(:include, self)
+  end
+end